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Linux kernel mirror (for testing)
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linux
1OCFS2 filesystem
2==================
3OCFS2 is a general purpose extent based shared disk cluster file
4system with many similarities to ext3. It supports 64 bit inode
5numbers, and has automatically extending metadata groups which may
6also make it attractive for non-clustered use.
7
8You'll want to install the ocfs2-tools package in order to at least
9get "mount.ocfs2" and "ocfs2_hb_ctl".
10
11Project web page: http://oss.oracle.com/projects/ocfs2
12Tools web page: http://oss.oracle.com/projects/ocfs2-tools
13OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
14
15All code copyright 2005 Oracle except when otherwise noted.
16
17CREDITS:
18Lots of code taken from ext3 and other projects.
19
20Authors in alphabetical order:
21Joel Becker <joel.becker@oracle.com>
22Zach Brown <zach.brown@oracle.com>
23Mark Fasheh <mfasheh@suse.com>
24Kurt Hackel <kurt.hackel@oracle.com>
25Tao Ma <tao.ma@oracle.com>
26Sunil Mushran <sunil.mushran@oracle.com>
27Manish Singh <manish.singh@oracle.com>
28Tiger Yang <tiger.yang@oracle.com>
29
30Caveats
31=======
32Features which OCFS2 does not support yet:
33 - Directory change notification (F_NOTIFY)
34 - Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
35
36Mount options
37=============
38
39OCFS2 supports the following mount options:
40(*) == default
41
42barrier=1 This enables/disables barriers. barrier=0 disables it,
43 barrier=1 enables it.
44errors=remount-ro(*) Remount the filesystem read-only on an error.
45errors=panic Panic and halt the machine if an error occurs.
46intr (*) Allow signals to interrupt cluster operations.
47nointr Do not allow signals to interrupt cluster
48 operations.
49atime_quantum=60(*) OCFS2 will not update atime unless this number
50 of seconds has passed since the last update.
51 Set to zero to always update atime.
52data=ordered (*) All data are forced directly out to the main file
53 system prior to its metadata being committed to the
54 journal.
55data=writeback Data ordering is not preserved, data may be written
56 into the main file system after its metadata has been
57 committed to the journal.
58preferred_slot=0(*) During mount, try to use this filesystem slot first. If
59 it is in use by another node, the first empty one found
60 will be chosen. Invalid values will be ignored.
61commit=nrsec (*) Ocfs2 can be told to sync all its data and metadata
62 every 'nrsec' seconds. The default value is 5 seconds.
63 This means that if you lose your power, you will lose
64 as much as the latest 5 seconds of work (your
65 filesystem will not be damaged though, thanks to the
66 journaling). This default value (or any low value)
67 will hurt performance, but it's good for data-safety.
68 Setting it to 0 will have the same effect as leaving
69 it at the default (5 seconds).
70 Setting it to very large values will improve
71 performance.
72localalloc=8(*) Allows custom localalloc size in MB. If the value is too
73 large, the fs will silently revert it to the default.
74localflocks This disables cluster aware flock.
75inode64 Indicates that Ocfs2 is allowed to create inodes at
76 any location in the filesystem, including those which
77 will result in inode numbers occupying more than 32
78 bits of significance.
79user_xattr (*) Enables Extended User Attributes.
80nouser_xattr Disables Extended User Attributes.
81acl Enables POSIX Access Control Lists support.
82noacl (*) Disables POSIX Access Control Lists support.
83resv_level=2 (*) Set how agressive allocation reservations will be.
84 Valid values are between 0 (reservations off) to 8
85 (maximum space for reservations).
86dir_resv_level= (*) By default, directory reservations will scale with file
87 reservations - users should rarely need to change this
88 value. If allocation reservations are turned off, this
89 option will have no effect.